The present subject matter relates to radio frequency identification (“RFID”) devices. More particularly, the present subject matter relates to approaches to forming the antenna of an RFID device so as to control the optical properties of the RFID device.
Devices incorporating RFID technology are widely used for a variety of applications, including vehicle security locks, access control to buildings, and inventory tracking systems in manufacturing, warehouses, in-store retail, and other operations enhanced by tracking functions.
RFID devices may have a variety of integrated components, among them an RFID chip containing data (e.g., an identification code) and an antenna electrically connected to the chip and responsible for transmitting signals to and/or receiving signals from another RFID device (e.g., an RFID reader system).
Commonly, the antenna is manufactured by patterning, etching, or printing a conductor on a substrate in a pattern that corresponds to the desired shape of the antenna. The tracks or conductive lines thereby composing the antenna will normally contain or include opaque conductive materials (such as silver, copper or aluminum), which do not allow light transmission. The substrate associated with the antenna is typically a thin, flexible material, which may be transparent or at least translucent or otherwise configured to allow for the passage of light therethrough. This sharp contrast between the opaque antenna and the light-transmissive substrate can interfere with the appearance of materials (such as fabric labels) placed in front of conventional RFID devices. This may be especially disadvantageous for articles for which the appearance of the article is critical to marketability. For example, the aesthetic appeal of articles such as apparel labels/tags having RFID inlays may be affected due to visibility of parts of the RFID inlays through the label/tag substrate. Ideally, in these applications, no RFID device structures (e.g., conductive lines crossing a label) should be visible.
One possible approach to this problem is the use of thicker, highly opaque fabric or paper as a substrate. Thicker materials, however, can be rigid resulting in discomfort to wearer of these garments. Therefore, it is desirable for the RFID device to be soft and flexible. in which case the use of thicker substrate material is not satisfactory. Moreover, while it is desirable that the parts of the RFID device such as the antenna be invisible, it is at the same time also desirable that the logo or branding of the article to which the RFID device is tagged or attached to, be visibly and aesthetically enhanced.
There are several aspects of the present subject matter which may be embodied separately or together in the devices and systems described and claimed below. These aspects may be employed alone or in combination with other aspects of the subject matter described herein, and the description of these aspects together is not intended to preclude the use of these aspects separately or the claiming of such aspects separately or in different combinations as set forth in the claims appended hereto.
Methods for manufacturing an RFID device with controlled optical properties are described herein. The method includes providing a conductive material on a substrate and processing the conductive material to separate an antenna from a periphery, with the periphery being retained on the substrate. The antenna is separated from the periphery through a gap, with at least a portion of the gap being formed along a perimeter of one or more branding symbols, such as a logo or other brand identifying mark, design, etc., formed on a substrate of the RFID device. In some embodiments, the RFID chip is electrically coupled to the antenna, but not to the periphery.
In some embodiments, the method is as described above, and the conductive material is processed, for example, by cutting (e.g., die cutting), laser cutting, and/or etching in order to separate an antenna from a periphery, with the periphery being retained on the substrate. In some embodiments, the method is as described above and the conductive material, e.g., the antenna, has first and second portions, which are separated from a periphery, with the periphery being retained on the substrate. In some embodiments, the method is as described above, and the RFID chip is associated with a strap substrate at least partially formed of an opaque material and configured to extend between the first and second portions of the antenna.
In some embodiments, the method is as described above and at least a portion of the gap has a width configured to allow for the passage of a predetermined amount of light therethrough, the configuration being able to depict desired shapes, logos, designs, marks, or other optical characteristics. In still other embodiments, at least a portion of the gap is formed along a perimeter of one or more branding symbols (e.g., logo or other brand identifying mark, design, etc.) formed on the substrate of the RFID device.
In still other embodiments, at least a portion of the gap is formed along a perimeter of the one or more branding symbols formed/printed in the substrate of the RFID device. In some embodiments, the method is as described as above and further includes printing a conductive material onto a substrate so as to define an antenna and a periphery. In some embodiments, an RFID chip is electrically coupled to the antenna, but not to the periphery. The printing includes creating a gap between the antenna and the periphery, with at least a portion of the gap having a width configured to allow for the passage of a predetermined amount of light therethrough, the configuration being able to depict or enhance desired shapes, logos, design, marks, or other optical characteristics.
In some embodiments, the method is as described above and further includes providing a conductive material and defining a gap in the conductive material to configure it as a substantially spiral-shaped antenna, with at least a portion of the gap being formed along a perimeter of one or more branding symbols formed on the substrate of the RFID device. RFID device includes a substrate, a conductive material associated with the substrate, and an RFID chip are also described herein. In some embodiments, the conductive material contains an antenna and a periphery, with the RFID chip being electrically coupled to the antenna, but not to the periphery.
In some embodiments, the RFID device is as described above and further include controlled optical properties. In some embodiments, the conductive material includes an antenna and a periphery separated by a gap, with the RFID chip being electrically coupled to the antenna, but not to the periphery, and with the gap having a width in the range of approximately 25 μm to 200 μm.
In some embodiments, the RFID device is as described above and the antenna has first and second portions, with the RFID chip being associated with a strap substrate at least partially formed of an opaque material and extending between the first and second portions of the antenna.
The embodiments disclosed herein are for the purpose of providing a description of the present subject matter, and it is understood that the subject matter may be embodied in various other forms and combinations not shown in detail. Therefore, specific designs and features disclosed herein are not to be interpreted as limiting the subject matter as defined in the accompanying claims.
The conductive material 12 may cover any portion of the substrate, but in one embodiment, is applied to an entire surface of the substrate. The portion of the substrate onto which the conductive material 12 is applied will have substantially uniform optical properties (i.e., that portion of the RFID device 10a will be substantially opaque, due to the presence of the conductive material 12). By applying the conductive material 12 to an entire surface of the substrate, the resulting RFID device 10a will have controlled, more uniform optical properties, as will be described in greater detail. Due to the conductive material 12 being applied in a manner that provides the RFID device 10a with more uniform optical properties, more flexibility is possible with the material composition of the conductive material 12 and the substrate, as described above. For example, the opacity of the substrate is not a consideration when the conductive material 12 is applied in a manner that is entirely controlling of the optical properties of the resulting RFID device 10a.
As also shown in
Regardless of how the antenna 14 and periphery 16 are defined, they may be provided in any suitable configuration without departing from the scope of the present disclosure. For example, in the embodiment of
In one embodiment, each gap 18 is narrow or has a small width, which may be in the range of approximately 25 μm to 200 μm. By providing a narrow gap or gaps 18, no appreciable amount of light will be transmitted through the gap(s) 18. This serves to maintain the uniformity of the optical properties of RFID device 10a, with the antenna 14 and periphery 16 (which is retained on the substrate) being opaque and with the gap(s) 18 therebetween being substantially non-transmissive of light, thus rendering the entire RFID device 10a (or at least the portion thereof in which the conductive material 12 is present) substantially, uniformly opaque. Another advantage of a gap or gaps 18 having a small width is that such a configuration allows for the conductive material 12 to present a substantially flat surface. A conventional RFID device will include larger spaces (e.g., on the order of approximately 10 mm) defined between portions of the antenna, which presents an uneven surface that may be difficult to print upon without significant distortion. Thus, by employing a narrow gap or gaps 18 to separate the antenna 14 from the periphery 16, the clarity of print applied to the RFID device 10a will be improved.
While it may be advantageous in many applications for the gap(s) 18 to be relatively narrow, it is within the scope of the present disclosure for all or a portion of a gap 18 to be wide enough to allow for an appreciable or predetermined amount of light to be transmitted therethrough. As described above, the gap(s) 18 may be provided in any configuration without departing from the scope of the present disclosure. As such, it may be desirable to provide a gap or gaps 18 (or one or more portions thereof) with a greater width and a configuration in the form of a logo or other desired pattern. In such an embodiment, an appreciable or predetermined amount of light will pass through the gap(s) 18 to display the logo or pattern, thereby acting as a visual enhancement for the RHD device 10a and an associated label or the like. For example, the gap(s) 18 are formed to be positioned along a perimeter of one or more branding symbols formed in the substrate. Forming gap(s) 18 along the perimeter of the one or more branding symbols including a logo or a pattern ensures that there is passage or transmission of sufficient light to enhance the visibility of the branding symbols, while ensuring that there is no or minimal light transmission through the antenna 14. Thus, the construction of the RFID device 10a enables achieving controlled optical properties. Therefore, the construction of the RHD device 10a ensures that there is no visual interference of parts of the RFID device such as the antenna 14 with the branding of the article to which the RFID device 10a is secured. Additionally, the design degrees of freedom associated with the RFID device 10a are also high since the gap(s) 18 can be customized to be formed according to the shape and size of the branding symbols and according to their relative positioning on the substrate. Alternatively, the gap(s) 18 can be formed along a portion of the substrate that carries additional information such as wash care or anti counterfeit details.
Regardless of the particular configuration of the antenna 14, it is electrically coupled to an RFID chip 24. On account of the antenna 14 being electrically isolated from the periphery 16, the periphery 16 is not electrically coupled to the RFID chip 24. The RFID chip 24 may be electrically coupled to the antenna 14 according to any suitable approach, which may include direct attachment of the RFID chip 24 to the antenna 14 (as in
When an RFID strap 26 is employed, a larger gap between two portions of the antenna 14 is required than what is needed for direct connection of an RFID chip 24. For example, while an approximately 500 μm slit may be sufficient for separating two portions of the antenna 14 for direct connection of an RFID chip 24 (as in
A comparison of
A comparison of
As in the embodiments of
According to yet another approach to reducing the visibility of a substrate through a gap defined in a conductive material, the RFID device may further include a masking member or material having optical properties (e.g., opacity) that are more similar to that of the conductive material than the substrate. In one embodiment, the masking member may be provided as a distinct layer, which overlays all or a portion of the gap, being positioned on the same side of the substrate as the conductive material or on the opposite side of the substrate. This is comparable to
Rather than being entirely uniform, the masking member may have varying optical properties. This may include the masking member including a plurality of regions or sections having optical properties that are similar to those of the conductive material, with the regions or sections being arranged in pattern, which may be random or non-random. For example,
The masking member 38 of
In yet another embodiment, rather than the masking member or material being provided as a separate layer, the masking member or material may be co-planar with and received by the gap 18. For example, paint or some other non-conductive masking member or material 42 may be at least partially positioned within the gap 18 to prevent light from passing through the gap 18 or at least reduce the amount of light that passes through the gap 18, as shown in
It will be understood that the aspects, embodiments and examples described herein are illustrative examples of some of the applications of the principles of the present subject matter. Numerous modifications may be made by those skilled in the art without departing from the spirit and scope of the claimed subject matter, including those combinations of features that are individually disclosed or claimed herein. For these reasons, the scope hereof is not limited to the above description but is as set forth in the following claims, and it is understood that claims may be directed to the features hereof, including as combinations of features that are individually disclosed or claimed herein.
The present application claims the benefit of U.S. Provisional Patent Application No. 62/880,804 filed Jul. 31, 2019, which is incorporated herein by reference in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/US2020/044433 | 7/31/2020 | WO |
Number | Date | Country | |
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62880804 | Jul 2019 | US |